Now for the longer version. I am speaking here about Retreats, etc and not weekly worship events, etc. We even charged for our Freshmen Survival which was the first day of class or the weekend before classes started. We wanted as many freshmen to come as possible.....and we charged for it.
Here is my reasoning. Free sometimes gives the message....not worth much. Free to sign up takes no commitment. One of our partner churches used to offer a Collegiate Retreat for free. Students just had to sign their name on the sign-up list at the church....and they did. It's just that the majority of them didn't show up for the Retreat. They signed their name....in case they should decide they wanted to go. For free, it took no decision or commitment to sign up for the Retreat. The Retreat was lightly attended and much of the food they had prepared for the large number who had signed up went to waste.
A deposit or sign up cost takes some commitment. Do I want to go to this? Is it at a time I can go? Do I need to make arrangements to get off from work? Paying some money takes some thought.
I believe in costs not being high. I even believe in loaning students money to go....on the 20 year pay plan. I believe in communicating that everything in life is not free. Commitment costs something. But, I never charged all that the event cost. But, it wasn't free!